Orange County Sheriff Jerry Demings described the shooter as a 45-year-old man who had been fired in April and had been previously accused of assaulting a co-worker. The attacker was not believed to be a member of any type of subversive or terrorist organization, he said.

The man was not charged when he was accused of battering the co-worker in June 2014, and his previous criminal record was otherwise minor — marijuana possession and driving under the influence, the sheriff said. The co-worker he allegedly beat up three years ago was not among the victims Monday, the sheriff added.

Shelley Adams said her sister, Sheila McIntyre, called her from the company’s bathroom during the shooting and kept repeating, “My boss is dead. My boss is dead.”

State and federal law enforcement officers converged on the industrial park in Orlando shortly after 8 a.m. after a woman ran from the awning business, Fiamma Inc., saying the gunman had told her to leave. She used the phone of a tile business across the street to call 911, said Yamaris Gomez, the tile store’s owner.

“All she kept saying was he was holding a gun and told her to get out,” Gomez said.

The sheriff said officers were dispatched within 45 seconds and arrived two minutes later. The FBI also responded, said Ron Hopper, who runs the FBI’s Orlando office.

Special Agent Danny Banks of the Florida Department of Law Enforcement said that while five people were killed, “seven others’ lives were saved due to the quick actions of the officers who arrived on the scene today.”

Banks said authorities had no reports of any specific threats the gunman made to people at the company or anyone else. He said the attack shows why people need to alert authorities if they learn of anything that could lead to violence.